Diffraction Definition and 1000 Threads

If I am given the width of the slit (b), wavelength of the light (λ), and the distance of the slit from the screen (D), how can I find the width of the central maximum (d)? My book says d/2=Dλ/b, but with no explanation and I don't understand why. Where does this formula come from? Thank you...

I'm a physics student, and working on a class project that requires coming up with a method to control the exit angle (diffraction angle) of a monochromatic light source. For example, taking a laser (monochromatic, coherent light source), spreading the beam, and directing the light at a piece...

Is it possible to infer particle properties from 2 sources diffraction with no slit/slits involved? Some explanations of experiments i can find, if i understand them correctly at all, relate to the possibility of concluding particle momentum, from absorption lines, when emanating from a single...

In https://www.sciencedirect.com/science/article/pii/S0378437109010401, the author claims that the interference pattern obtained in the double-slit experiment does not need a wave description of matter, and can be accounted for by the "quantized momentum transfer" from the slits to the electron...

Hi I am doing an electron gun diffraction right now and I wonder why the angle below is 2 phi. What I think about it that it's actually the results of two waves one is shown below and the other is a wave with the same accident angle but negative "those two rays will be symmetric around the...

I've been exposed to this notion in multiple classes (namely math and physics) but can't find any details about how one would actually calculate something using this principle: Diffraction in optics is closely related to Fourier transforms and finding the Fraunhofer diffraction of an aperture...

I know the textbook definitions and descriptions of the phenomenon, but I'm hoping for a fundamental WHY. I can see that when a water wave passes an obstacle, the wave spreads out into that object's shadow because the wave's energy is not constrained to any direction and so it will move out in...

Is anyone did experiment on diffraction with single particle at a time? Do they get diffraction pattern? I referred particle as both electron and photon And I want to know any experiment( classical, or single particle at time) don't show any diffraction pattern in single slit experiment.

I know that a plane wave going through a slit becomes a spherical wave because of a Huygens-Fresnel principle. Can someone explain to me why a plane wave splits into many plane waves with different directions when going through a plate with varying thickness? Can someone explain me this image?

Homework Statement i don't understand where the 1.22 number comes from like in ## sin \theta = 1.22 \lambda /D ## so i tried to derive but to not much help Homework Equations electric field at distance R due to slit of length D is ## E = \frac{\epsilon_l D}{R} sinc(\frac{kD}{2}sin \theta)sin(wt...

Hello! I'm very interested in knowing your opinion on how close my model is to the Fresnel Diffraction by an opaque barrier, as seen here: http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/difopa.html#c1 My model: Sorry for the low quality image.

I’ve got a laser that I want to use to measure a straight line (preferably within about a millimeter) over about 2000 ft. My first thought was to focus my laser better and bring up a card until it cut the beam completely, but focusing down to a millimeter point so far away feels pretty...

Hi. The angular resolution is calculated through $$\theta=1.22\frac{\lambda}{D}\enspace.$$ It's the first zero of the intensity function (in small-angle approximation) of the Airy disk...

when a single photon is supposed to form a diffraction pattern, they hit the detector by different angles at the slit. so then what cancels this photon's momentum change? what happens to the photon's energy/frequency?what measurements has been done to confirm the answer?

Explanations of 2-slit interference sometimes show the interference pattern compared to a 1-slit diffraction pattern, and state that the latter represents a limit or envelope for the former. Is it correct to interpret the patterns as representing (directly or indirectly) the number of photons...

Homework Statement I need to calculate the error of an average value (N for diffraction grating). My results were 4 different average angles. With which I calculated their uncertainty using std. Using equation (1), I found the number of lines per meter (N) with a known wavelength (λ) and the...

Can anyone explain me the pattern that is obtained from selected area diffraction? What does it show? What are the dots? What are the rings? (example: http://www.microscopy.cz/html/images/2605_1_d0f65ce7_fig2.png) I know that during X-ray powder diffraction, radiation is shined at the powder at...

1. A white light shines vertically down on a horizontal CD ROM disc. The disc is viewed by a teacher whose eye is a horizontal distance 0.50 m from the disc and 0.35 m vertically above its horizontal plane, Figure 1.2. A yellow light of wavelength 590 nm is observed due to first order...

Homework Statement In picture, first-order reflection from the reflection planes shown occurs when an x-ray beam of wavelength ##0.260 nm## makes an angle ##\theta=63.8°## with the top face of the crystal. What is the unit cell size ##a_0##? Homework Equations Bragg law $$d=\frac{ n...

I've recently come across this problem: Answer true or false. If light shines through 2 slits, will the diffraction pattern always be within the interference pattern. I don't understand this question, however. How can the interference and diffraction pattern be separated in this situation...

Homework Statement A square aperture with a side of length 0.5 mm is illuminated with light of wavelength 550 nm. At what distance from the aperture would the Fraunhofer diffraction pattern have a central maximum with a width also equal to 0.5 mm? What can you say about the Fraunhofer condition...

Homework Statement In double slit interference , the angle between the center bright fringe and the path length (aka the angle used to find the path length difference) can be approximate as a small angle. However, we cannot assume the angles of bright fringes due to diffraction gratings are...

I am trying to understand how a blazed diffraction grating works and came across a deduction I don't understand. I believe that you don't need to know much about optics to answer this question as it is more geometry related. I have the diagram below of a diffraction grating with all the relevant...

Hey, I am currently busy with studying solid state physics and looking at diffraction theory. Following link explains Frauenhofer diffraction pretty good: http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/mulslid.html#c3 Let's assume a N=6 multiple slits. Its diffraction pattern depends on slit...

Homework Statement Homework Equations Path difference is nλ at maxima, (n+0.5)λ at minima The Attempt at a Solution I think the phase difference between S1 and S2 is not 0 anymore, because the wave effectively takes a longer distance by going through S2. Thus, there is no longer a central...

Homework Statement Find an approximate expression for the ratio of the power densities at the principal maximum to that at the first secondary maximum on either side, in the Fraunhofer diffraction pattern of an N-slit multiple aperture. Assume that the slits are much narrower than their...

Homework Statement My question is at https://imgur.com/a/lDOUzjY . The de Broglie wavelength of the atoms in question is 45 pm. The distance from the slits to the detection plane is 1.95m. Each slit width is 1 micrometer. The distance between the slits is 8 micrometers. 2. Homework Equations...

Homework Statement Suppose you wanted to be able to see astronauts on the moon. What is the smallest diameter of the objective lens required to resolve a 0.60 m object on the moon? Assme the wavelength of the light is near the middle of the visible spectrum: 550 nm yellow light. (in m) A...

I am trying to understand diffraction on periodic structured in solid state physics.Q is the source of the spherical wave. R the vector to the object and R+r the vector to the scattering centre P, which gives us a another spherical wave. All spherical waves are considered as plane waves due to...

Homework Statement Two slits (of width ##a=39 \mu m##) are lighted up with a monocromatic wave of ##\lambda=632,8 nm##. The distance between slits and the screen id ##D=4 m##. The distance between the slits id ##d=195 \mu m##. In front of the slits there are a convergent lens with focal length...

Homework Statement If a green laser is (wavelength = 532nm) sent through two slits with a separation of 127 um, how wide (in total) would the 11 green dots formed be if they were projected onto a screen 1.25m away from the slits? Refer to this diagram sorry for bad quality...

1. What is the advantage of using class 2 laser light? I would really appreciate if reference source is also given!Homework Equations Not needed.[/B]The Attempt at a Solution Well, I thought that using monochromatic light would made it easier to measure the distance between fringes. And also...

Homework Statement The Attempt at a Solution Hi All, I have two issues with this question. First of all when I put the given values into the Bragg condition for diffraction I get two different wavelengths when the question implies there is only one. Secondly, I don't know how I can...

I don’t understand why do we use power in this experiment. If we use powder, the d spacings of each crystalline will be oriented randomly, why won’t the angle of reflection changes? I don’t understand the idea of using powder in the experiment. Thank you so much

Homework Statement The Attempt at a Solution Hi All! This is probably going to have a very simple answer. I'm stuck on question (b)(ii). The only equation I can find with the ruling width in it is the one shown and I can't find a way to calculate is as I don't know Beta. Thanks

For what ratio of slit width to wavelength will the first minima of a single-slit diffraction pattern occur at $\pm 90°$? The thing is, when I did it, I used the formula $sin\theta = \frac{n\lambda}{a}$, and used the fact that $m = 1$ and $\pm 90°$ to solve for $\frac{a}{\lambda}$. However, I...

I was reading a book called Catching the Light; a book on the history and other interesting things about light. There is a discussion in the book about refraction such as one might see when looking at a stone at the bottom of a pond when viewed at an angle. I've always just thought of the...

Homework Statement SINGLE SLIT Why does the intensity at maxima decrease further away from the central maxima in a single slit diffraction. DOUBLE SLIT Slit width: Why is the intensity of a double slit interference pattern the same at each maxima. (constructive interference) When the slit...

Homework Statement Consider ultrasound with a frequency of 40 kHz. (a) What is the wavelength and period of a 40 kHz sound wave? (b) The slit width required to give the first order diffraction minimum at thirty degrees. (c) Calculate the angles at which the first three minimums should be...

If I understand the phenomenon correctly; whenever we capture an image using a telescope, because the light that's emitted from a distance object acts like a wave, we notice a diffraction pattern in our image. Now, in the double slit experiment (I didn't create the image, excuse the "slot"...

Homework Statement Monochromatic light of wavelength 690nm passes through a diffraction grating with 300 lines per mm, producing a series of maxima on a screen. What is the greatest number of maximas that can be observed? A) 4 B) 5 C) 8 D) 9 Homework Equations n*wavelength = d*sin x The...

I'm looking for a free software I could use to simulate near field diffraction from a 2d periodic array of conductors and dielectrics placed on the surface of a dielectric slab.

Hi, I recently tried to create diffraction gratings using the negative film of a disposable camera. I designed them so the 'slits' were black and the rest was white so on the negative film the slits would be transparent and the rest would be opaque. It didn't work however. Does anybody have any...

[Mentors' note: This thread has been edited to change the level tag from 'A' to 'I'] Hello guys, I want the deduction part of- diffraction at single slit: Plz sent me the notes of this.

Hi, I'm doing my third year project on diffraction gratings and patterns and analysaing them via computer software and Fourier transforms. I'm going to design my diffraction gratings this week and then create them via taking a picture with a disposable camera and using the negative film. What...

In his second lecture of the QED series (see below), Prof. Richard Feynman explains the phenomenon of reflection from a plane mirror, and then the working of a diffraction grating with his theory of arrows (probability amplitudes), and we see that how the new theory, which is much moved from the...

Hello, below is the screenshot from the book INTRODUCTION TO MODERN DIGITAL HOLOGRAPHY With MATLAB (TING-CHUNG POON, JUNG-PING LIU). This book is free to download. There is a script for Fraunhofer diffraction pattern and equation 1.40 is Fraunhofer diffraction formula in terms of Fourier...

Homework Statement Homework EquationsThe Attempt at a Solution [/B] I did not understand what is meant by the center of the pattern here. a) I have ## \delta \theta_{hw} = \frac { \lambda }{Nd \cos{\theta }} ## For central maximum ## \theta = 0##, so central line has less width than...

I have a problem understanding diffraction and its dependence on the wavelength of the source. We know that light cannot travel through obstacles of the size of everyday objects while sound can. That is why we can hear sound across the corner of a building but we can't see a light source across...

Hi, This is my first post so apologies if I'm not clear enough or if I am posting in the wrong place. I am doing my 3rd year project at university and I am creating diffraction gratings. My supervisor shown me a Canadian note and if you shine a laser through the maple leaf it will shine on the...